Field of the Invention
The present invention relates to an imaging apparatus having a focus adjustment function based on auto focus adjustment of an imaging plane phase difference scheme.
Description of the Related Art
RAW image data is used to perform a development process after photographing in a personal computer (PC) or the like with respect to an image captured by a camera. The RAW image data is image data output by an imaging element or image data before development and is saved in a memory in reversible compression without reducing a size according to irreversible compression. A process of saving a RAW image is disclosed in Japanese Patent Laid-Open No. 2014-53701.
In auto focus adjustment (hereinafter abbreviated to AF) of an imaging plane phase difference scheme, pixels of the imaging element are subjected to a pupil division process and focus adjustment is performed according to a correlation calculation of an image division. The image division subjected to the pupil division process can be used in a field of application other than focus adjustment. At this time, a process of saving the divided image data as a RAW image separately from normally captured image data is performed.
A decrease in a light amount referred to as shading may occur in each of image divisions according to a positional relationship between an incident angle of a light flux and a photodiode of an imaging element in terms of a pupil-divided image. Thus, a shading correction process is performed. Because the shading is changed by factors such as an image height of an image, an exit pupil distance specific to a lens, or an F number, it is difficult to perform estimation after photographing. For this reason, if the shading correction process is not sufficiently performed, there is a possibility that image quality may be deteriorated when a pupil-divided image is used after photographing.